Revelation 12 peels back the curtain and reveals the ‘rest of the story’ behind the nativity scene. What looks like an ordinary baby being born in a stable surrounded by an adoring mother and father and a few shepherds and perfectly-behaved sheep is actually the battle scene foretold in Genesis 3: “I will put enmity between you and the woman, and between your offspring and her offspring; he shall bruise your head, and you shall bruise his heel.”
“The dragon stood before the woman who was about to give birth, so that when she bore her child he might devour it. She gave birth to a male child, one who is to rule all the nations with a rod of iron.”
The Christmas story embodied a key moment in cosmic battle unfolding between Christ and the spiritual forces of Satan. The birth of Christ was a key victory one in the conflict, for Christ’s “incarnation, obedience, sacrifice, and exaltation forever disqualify Satan from accusing believers.” Satan would recruit all the forces of the world against the rising climax of the redemptive plan, tempting Christ in the wilderness, setting up all the religious and secular authorities against him, causing even his own disciple to betray him, and finally crucifying him.
But just as Genesis 3:15 foretold, all of Satan’s efforts merely bruised Christ’s heel. His death itself was the final, complete victory, crushing the serpent’s head and forever declaring victory over sin, death, and hell.
We celebrate Christmas—because the baby born in the manger has defeated our greatest foe. We celebrate Christmas—because His life was the climax of the Cosmic Drama, the very drama we find ourselves in today. And we celebrate Christmas—because Christ’s birth, death, and resurrection offers the only gospel hope that can transform our souls.
 ESV Student Study Bible, Revelation 12:1-17.